In the ink jet recording method, small droplets of ink are ejected from fine nozzles and attached to a recording medium to carry out recording. This method is characterized by being able to record high resolution and high quality images at a high speed with a relatively inexpensive apparatus.
In recent years, research has been carried out into directly recording (printing) labels and the like for products on soft packaging films by the ink jet recording method with respect to soft packaging films such as PET films. In addition, soft packaging films have applications for packaging foods and the like and since high safety is required for such applications, it is desirable to use water-based inks for the printing described above. In the case of using water-based inks, a heat drying process may be performed after the printing.
In addition, since the target recording surface of the soft packaging film is formed of, for example, a plastic material such as polyolefin, nylon, or polyester, the surface is often transparent or translucent. Therefore, when ink jet recording is performed, a predetermined image may be formed using color ink on a layer formed of white ink called an underlayer which covers the background (refer to, for example, JP-A-2014-094495). JP-A-2013-177526 proposes a white ink for ink jet recording applicable to such an under layer.